Derivatives of n-methylpiperazine

ABSTRACT

N-METHYL-N&#39;&#39;-ETHYL-PIPERAZINES IN WHICH THE ETHYL RADICAL IS B,B-DISUBSTITUTED WITH (1) A PHENYL OR PHENOXYMETHYLENE RADICAL WHICH IS UNSUBSTITUTED OR SUBSTITUTED IN THE RING WITH STRAIGHT OR BRANCHED ALIPHATIC CHAINS HAVING 4 TO 12 CARBON ATOMS OR CYCLOALKYL GROUPS HAVING 5 TO 6 CARBON ATOMS OR WITH 2 OR 3 CHLORINE ATOMS OR WITH 2 CHLORINE ATOMS AND A NITRO GROUP, AND (2) A BENZOLYOXY OR PHENOXYACETYLOXY RADICAL WHICH IS UNSUBSTITUTED OR SUBSTITUTED IN THE RING WITH 1, 2 OR 3 CHLORINE ATOMS OR WITH 2 CHLORINE ATOMS AND A NITRO GROUP OR A BENZYLOXY RADICAL SUBSTITUTED IN THE RING WITH 1, 2 OR 3 CHLORINE ATOMS; AND PHARMACEUTICALLY ACCEPTABLE ACID ADDITION SALTS THEREOF. ALL OF THE COMPOUNDS HAVE ANTIBACTERIAL AND ANTIPROTOZOAN ACTIVITY.

United States Patent 3,580,914 DERIVATIVES F N-IVEETHYLPIPERAZINE Andrea Pedrazzoli and Leon DallAsta, Milan, Italy, assignors to Societe dEtndes de Recherches et dApplicafion Scientifiques et Medicaies E.R.A.S.M.E., Paris, France No Drawing. Filed Aug. 14, 1967, Ser. No. 660,227 Claims priority, application Great Britain, Aug. 23, 1966, 37,827/67 Int. Cl. C07d 51/64 US. Cl. 260268 2 Claims ABSTRACT OF THE DISCLOSURE N-methyl-N'-ethyl-piperazines in which the ethyl radical is {3,[3-disubstituted with (1) a phenyl or phenoxymethylene radical which is unsubstituted or substituted in the ring with straight or branched aliphatic chains having 4 to 12 carbon atoms or cycloalkyl groups having 5 to 6 carbon atoms or with 2 or 3 chlorine atoms or with 2 chlorine atoms and a nitro group, and (2) a benzoyloxy or phenoxyacetyloxy radical which is unsubstituted or substituted in the ring with 1, 2 or 3 chlorine atoms or with 2 chlorine atoms and a nitro group or a benzyloxy radical substituted in the ring with 1, 2 or 3 chlorine atoms; and pharmaceutically acceptable acid addition salts thereof. All of the compounds have antibacterial and antiprotozoan activity.

The present invention relates to new derivatives of N- methylpiperazine, which are therapeutically useful, and their process of preparation; the new products of the invention have the general structural formula:

N-OHa in which:

The process of preparation of the compounds according to the invention can be represented by the following reaction scheme:

R-CH-CHz-N in which X represents a halogen atom and R and R have the same meanings as above.

The compounds of the invention where R is the radical of an acid are obtained by the reaction of the amino alco hol (I) with an acid halide R X, preferably an acid chloride, in an inorganic solvent such as benzene, toluene, Xylene or tetrahydrofuramm the presence of a basic hydrogen acceptor, such as the tertiary amines, esg. triethylamine, pyridine or dimethylaniline, to give the corresponding ester (III).

The reaction takes place at room temperature and, in order to complete it, it is preferable to heat the mixture under reflux for some hours.

"ice

The compounds of the invention, Where R is a substituted benzyl, are obtained by reaction of the amino alcohol with the halide of a substituted benzyl, in an inert organic solvent such as benzene, toluene, Xylene or tetrahydrofuran, in the presence of an alkali metal or alkaline earth metal hydride, preferably sodium hydride.

The reaction takes place at a temperature of 145 C., preferably 1l0-120 C., for 5-20 hours, preferably for 15-19 hours.

The products of the invention are separated in the form of salts with pharmaceutically useful inorganic or organic acids, such as the hydrochloride, sulphate, phosphate, or citrate.

The starting materials are obtained by the following procedures:

(a) In the case where R is a substituted phenyl radical as indicated above, the w-halo-ketone (IV) is reacted with N-methylpiperazine according to known techniques and the product obtained (V) is reduced with sodium borohydride to give the desired intermediate (VI) where R R and R, can be the same or different and each represents a straight or branched aliphatic chain containing 4 to 12 carbon atoms or a cycloaliphatic ring containing 5 or 6 carbon atoms or chlorine;

(b) In the case where R is a substituted phenoxy-methylene, the epoxide (VII) is reacted with N-methyl-piperazine to give the desired intermediate (VIII):

0 where R R and R can be the same or difierent and have the meaning defined above in (a).

The compound (VIII) can also be synthesized by the reaction:

In this case, the 1-(2,3'-epoxypropyl)-4-methyl-piperazine (IX) is reacted according to known techniques with an aqueous alkaline solution of the phenate.

All the products of the invention have a remarkable antibacterial activity, their spectrum extending both to Gram-positive and Gram-negative organisms; also, they have a clear action on Candida albz'cans and on other mycetes.

The compounds of the invention also have a marked antiprotozoan activity, especially trichomoricidal and ami- 1- [B- (2,4-dichlorobenzoyloxy B- (3 ',4'-dichlorophenyl ethyl]-4-methyl-piperazine dihydrochloride 89.2 g. of 3,4,w-trichloroacetophenone in 240 ml. of anhydrous ethyl ether were treated for minutes with a solution of 84 g. of N-methyl-piperazine in 160 ml. of anhydrous ethyl ether. After 3 hours of agitation at room temperature, the solution was filtered and concentrated under vacuum and, by crystallization of the residue from isopropanol and petroleum ether, 40.8 g. of 3,4-dichlorow-(4'-methylpiperazin 1'-yl)-acetophenone was obtained; M.P.-=76-78 C.

40.8 g. of 3,4 dichloro-w-(4-methylpiperazin-1'-yl)- acetophenone in 150 ml. of methanol were treated at 18- 20 C. for minutes with a solution of 4.65 g. of sodium borohydride in 10 ml. of NaOH+25 ml. of water. After 30 minutes of agitation, the mixture was filtered and from the solution, by dilution with 150 ml. of water, 39 g. of 1 (3,4' dichlorophenyl) 2 (4" methylpiperazin- -yl)-ethan-1-ol was Obtained; M.P.=121123 C.

To 39 g. of 1-(3',4'-dichlorophenyl)-2-(4"-methylpiperazin-1"-yl)-ethan-1-ol in 530 ml. of toluene, 28.8 g. of 2,4-dichlorobenzoyl chloride in 55 ml. of anhydrous toluene were added and then 14.1 g. of triethylamine in 110 ml. of anhydrous toluene. After heating under reflux for 2 hours, the mixture was cooled, filtered and concentrated under vacuum and the residue was treated with a solution of hydrochloric acid in isopropanol to obtain 53.6 g. of crude product. After two crystallizations from 95% etha- I101, 47 g. of 1-[B-(2",4"-dichlorobenzoyl)fl-(3,4-dichlo rophenyl)-ethyl]-4-methyl-piperazine dihydrochloride was obtained; M.P. =209212 C.

EXAMPLE 2 1 (2,4',6'-trichloro-phenoxy)-2-(2",4-dichloro-benzoyloxy)-3-( "'-methyl-piperazine- "-yl)-propane dihydrochloride 1-(2',4', '-trichlorophenoxy)-2-3-epoxypropane was obtained in the following manner:

49 g. of 2,4,6-trichlorophenol and then 26 g. of epichlorhydrin were added to a solution of 16.2 g. of 85% KOH in 250 ml. of water. After agitation for 3 hours at room temperature, the mass was extracted with 150 ml. of ethyl ether. From the ethereal solution, 29.2 g. of 1-(2,4,6'-trichlorophenoxy)-2,3-epoxypropane were obtained. A solution of 29.2 g. of 1-(2',4',6'-trichlorophenoxy)-2,3-epoxypropane+1l.5 g. of N-methyl-piperazine in 88 ml. of absolute alcohol were heated under reflux for 2 hours. After concentration under vacuum, the residual oil was treated with a solution of hydrochloric acid in isopropanol to obtain 49 g. of crude product. By crystallization from isopropanol, 37.1 g. of 1-(2',4',6'-trichlorophenoxy)-3-(4"- methylpiperazin-1-yl)-propan-2-ol dihydrochloride were obtained; M.P.=218220 C.

37.1 g. of 1-(2',4,6-trichlorophenoxy)-3-(4"-methylpiperazin-1"-yl)propan-2-ol dihydrochloride in 800 ml. of anhydrous benzene were treated with 21.7 g. of 2,4-dichlorobenzoyl chloride and then 20.85 g. of triethylamine dissolved in 120 ml. of anhydrous benzene were added. The mixture was heated under reflux for 2 hours, filtered and then the benzene solution was washed with water. After drying, the hydrochloride was precipitated with a solution of hydrochloric acid in isopropanol. After crystallization of the crude product from ethanol, 49 g. of 1-(2,4,6'-trichlorophenoxy) 2 (2,4"-dich1orobenzoyloxy)-3- (5'-methylpiperazin-1"'-yl)-propane dihydrochloride were obtained; M.P.=216--218 C.

EXAMPLE 3 1 (2,4',6-trichlorophenoxy)-2-(2",4"-dich1orobenzoyloxy)-3-(4"'-methylpiperazin-1"-yl) propane dihydrochloride 46.8 g. of 1-(2',3-epoxypropy1) 4 methylpiperazine were introduced at room temperature into a solution of 59.2 g. of 2,4,6-trichlorophenol in 19.2 g. of KOH-l- 300 ml. of water. After agitation for 8 hours, the mass was extracted with 200 ml. of methylene chloride. The oil obtained by concentration of the solution was dissolved in isopropanol and treated with a solution of a hydrochloric acid in isopropanol to give 56 g. of crude product. After crystallization from isopropanol, 43.5 g. of 1-(2,4',6-trichlorophenoxy) 3 (4-methylpiperazin- 1" yl) propan 2 ol dihydrochloride were obtained; M.P.=218220 C. The preparation then continued as indicated in Example 2.

EXAMPLE 4 N-methyl-N'-[,8-(4-chlorobenzyloxy)-;8- (4'-cyclopentylphenyl)-ethyl]-piperazine dihydrochloride A mixture of 28.8 g. (10.1 moles) of N-methyl-N-[,B- hydroxy-B-(4-cyclopentyl-phenyl)ethyl] -piperazine, 5.3 g. (0.11 mole) of sodium hydride in 50 p. oily suspension and 300 ml. of anhydrous toluene was heated at C. for 1 hour. The mixture was cooled to 50 C. and treated with a solution of 17.7 g. (0.11 mole) of p-chloro- 'beuzyl chloride in 50 ml. of anhydrous toluene.

The mixture was heated under reflux for 16 hours, then cooled and treated with 350 g. of ice and the aqueous solution was separated and rewashed with water.

The organic phase was extracted with 300 ml. of 2 N HCl. The acidic solution rendered alkaline with 40% NaOH was extracted with ethyl ether. The concentrated and dried ethereal extract gave 35 g. of dense oil.

The oil dissolved in isopropanol and acidified with HCl gave 21 g. of crystals which were recrystallized from a 3.2 mixture of isopropanol and ethanol to give 17 g. of product having a melting point=223 225 C.

From the concentrated combined mother liquors, another 5.3 g. of product having a melting point=222 -224 C. was obtained.

EXAMPLE 5 N-methyl-N- [,6- (trichloro-2,4,5-benzyloxy) -,B- (dichloro- 3 ',4'-phenyl) -ethyl] -piperazine dihydrochloride A mixture of 23 g. (0.1 mole) of N-methyl-N-[B-hydroxy-B-(dichloro-3,4-phenyl)ethyl]-piperazine, 4.8 g. of sodium hydride in 50% oily suspension and 250 ml. of

5 anhydrous toluene was heated at 120 C. for 1 hour. The mixture was cooled to 50 C. and treated with a solution of 23 g. (0.1 mole) of trichloro-2,4,5-benzy1-chloride in 40 ml. of anhydrous toluene. The mixture was again heated to 120 C. for 18 hours and then cooled and treated with 300 g. of ice, the aqueous solution being separated and rewashed with water. The organic phase was extracted with 350 ml. of 2 N HCl. From this acidic solution, by

alkalinisation with 40% NaOH and extraction with 300 m1. of ethyl ether, an ethereal solution of the base was obtained which, with HCl, gave 26 g. of crude product. After crystallization from ethyl acetate-l-isopropanol, 17.5 was obtained having a melting point=204-208 C.

Various products according to the invention, prepared by the reaction schemes set out above, are included in the following table.

TABLE R-CH-CHz-N N-om Compound Formula of product Melting Number R R1 obtained point 0.)

CH3 Cz4H3oC1zN2O22HCl 207-208 om-JJ-Q- 01 00-- 2 Same as above CzaHagOlzNzOzZHCl 185. 5-187 3 Q ..do onnaflolzNzolznm 203-206 4 Same as above Cl C2sH31C1 N203.2HC1 212-214 C1OCH2CO 5 C1 C1 C20H21C13N202-2HC1 215-217 6.. Same as above 01 Same as above 230432 7 .mfl O1C0 -.ao. 245-247 01 s an Ol-QOQ- CzoHzuChNzOzBHCl 210-212 01 9 .do o1 l0- GzoH gC1 NzOz.2HC1 209 211 c1 01 1o o1- OCHzo1-ooofln oltmotznol 224-226 01 '01 11 o1- o-omo1-o-0H2o0 CzzHzzClgNz04.2HCl 215-218 c1 c1 12 01G omQ-o-omwo- CziHgOhNzOaflHCl 222-2245 13 Same as above til-@0112- ozomaoumoznoi 240-243 14 -d0 C1 CzuHggChNzO. 2HO1 237-240 l Orystallised with molecule of ethanol. b Hygroscopie product.

We claim: 1. A compound selected from the group consisting of (1) a compound of the formula TABLE-Continued Compound Formula of product Melting Number R1 obtained point C.)

15 ..do (I31 OzoHzrGhNzO. 2HO1 204-208 16 025E330 IN 20. 21101 223-225 Cl- CH2- 17 Same as above C1 C H 1O1 N2O. 2H0] 227-229 I Cl is 01 cwnuoizNzo. 21101 I 215-219 C1 CH2 I 19 Same as above CI C25H35C13Nz0. 2H0! 195-199 20 l C21H24Ci4NzOz. H01 95-96. 5

nitro and (2) a pharmaceutically acceptable acid addition salt thereof.

2. A compound as claimed in claim 1 which is an addition salt with hydrochloric, sulphuric, phosphoric or citric acid.

References Cited UNITED STATES PATENTS 2,928,834 3/1960 Shapiro et a1 260-268 NICHOLAS S. RIZZO, Primary Examiner R. V. RUSH, Assistant Examiner U.S. CL. X.R. 260-999 

